A Golden Plate

W.S. Harris. Observations on the Effects of Lightning on Floating Bodies: with an Account of a New method of Applying Fixed and Continuous Conductors of Electricity to the Masts of Ships, 1823

In early scientific books, it’s perfectly common to find illustrations depicting experiments. Much less common, however, are books whose illustrations actually are experiments.

William Snow Harris’ Observations on the Effects of Lightning on Floating Bodies is a short treatise on some methods of protecting ships from lightning. One of the plates in this book contains models of three different lightning protection systems, each executed in real gold. An electric current was then passed through each of the illustrations. By following the path of oxidation, we see exactly how lightning would travel through the system.

W.S. Harris. A Series of Papers on the Defence of Ships and Buildings from Lightning, 1835

While the Vail Collection is home to a similar title by Snow Harris containing the same plate, his Observations on the Effects of Lightning is fascinating beyond this novel form of illustration. In the Vail Collection copy, written in Snow’s own hand, we encounter the author’s explanation for why he believes a tubular metal conductor is more efficient than a conductor made of solid metal.